Electrostatic 3-d printer using layer and mechanical planer

ABSTRACT

A three-dimensional (3-D) printer includes build and support material development stations positioned to transfer layers of build and support materials to an intermediate transfer surface. The intermediate transfer surface transfers a layer of the build and support materials to a platen each time the platen contacts the intermediate transfer surface. A sensor detects the thickness of the layer on the platen, and a mechanical planer is positioned to contact and level the layer on the platen as the platen moves past the mechanical planer. Additionally, a feedback loop is electrically connected to the sensor and the mechanical planer. The mechanical planer adjusts the amount of the build material and the support material removed from the layer based on the thickness of the layer on the platen, as determined by the sensor.

BACKGROUND

Systems and methods herein generally relate to three-dimensional (3-D)printing processes that use electrostatic printing processes.

Three-dimensional printing can produce objects using, for example,ink-jet printers. In one exemplary process, a platen moves relative toan ink-jet to form a layer of build and support material on the platen,and each layer is hardened using a UV light source. These steps arerepeated layer-by-layer. Support materials generally comprise acid-,base- or water-soluble polymers, which can be selectively rinsed fromthe build material after 3-D printing is complete.

The electrostatic (electro-photographic) process is a well-known meansof generating two-dimensional digital images, which transfer materialsonto an intermediate surface (such as a photoreceptor belt or drum).Advancements in the way an electro-photographic image is transferred canleverage the speed, efficiency, and digital nature of printing systems.

SUMMARY

Exemplary three-dimensional (3-D) printers include, among othercomponents, an intermediate transfer surface, such as a drum orintermediate transfer belt (ITB), and build and support materialdevelopment stations positioned to transfer (e.g., electrostatically ormechanically) build and support material to the ITB. The build andsupport material development stations transfer layers of the build andsupport materials to the ITB.

A transfuse station is adjacent the ITB, and a platen having a flatsurface is positioned to repeatedly contact the ITB. The platen movesrelative to the ITB, and the ITB transfers a layer of the build andsupport materials to the flat surface of the platen each time the platencontacts one of the layers on the ITB at the transfuse station tosuccessively form a freestanding stack of the layers on the flat surfaceof the platen.

A sensor detects the thickness of the layer on the platen, and amechanical planer is positioned to contact and level the layer on theplaten as the platen moves past the mechanical planer. The mechanicalplaner makes the top of the layer parallel to the flat surface of theplaten and reduces the thickness of the layer. Additionally, a feedbackloop is electrically connected to the sensor and the mechanical planer.The mechanical planer adjusts the amount of the build material and thesupport material removed from the layer based on the thickness of thelayer on the platen, as determined by the sensor.

In one example, the mechanical planer is an angled blade (e.g., a bladepositioned at a non-parallel and non-perpendicular angle to the flatsurface of the platen). Further, such a blade is movable, and anactuator is connected to the movable blade. The actuator moves themovable blade toward and away from the platen. Also, a cleaningstructure is located in a fixed position, and the cleaning structurecontacts and cleans the movable blade as the actuator moves the movableblade past the cleaning structure. This structure can additionallyinclude a collection tray adjacent the mechanical planer. The collectiontray is positioned to collect the build and support material removedfrom the layer by the mechanical planer.

These and other features are described in, or are apparent from, thefollowing detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary systems and methods are described in detail below,with reference to the attached drawing figures, in which:

FIGS. 1-11 are schematic cross-section diagrams partially illustratingprinting devices herein;

FIG. 12 is an expanded schematic diagram illustrating devices herein;

FIGS. 13-19 are schematic cross-section diagrams partially illustratingprinting devices herein;

FIG. 20 is a schematic diagram illustrating a printing device herein;

FIG. 21 is a schematic diagram partially illustrating a printing deviceherein; and

FIG. 22 is a schematic diagram illustrating a development device herein.

DETAILED DESCRIPTION

As mentioned above, electrostatic printing process are well-known meansof generating two-dimensional (2-D) digital images, and the methods anddevices herein use such processing for the production of 3-D items (for3-D printing). However, when performing 3-D printing using electrostaticprocesses (especially those that use an ITB), the thickness uniformityand surface characteristics of each layer should be controlled toproduce a well formed, accurate final 3-D part. Once the layers areplaced on top of each other, any non-uniformity in the thickness of theindividual layers, or mis-registration between the part and supportmaterial creates a malformed and/or objectionable final part due to theadditive nature of the non-uniformities.

In view of such issues, the devices herein perform a leveling process toensure the dimensional accuracy of the final part, as well as, thepart-to-part repeatability. The devices herein use a leveling processfor improving part uniformity in a 3-D printing architecture usingelectrophotography.

To provide good development and transfer properties, the particle sizedistribution of build and support material should be tight and stable,to ensure uniform layer thickness. However, larger size particles createvoids and non-uniformity in each layer that must be dealt with in thetransfuse assembly. Small errors in each individual layer accumulate tolarger dimensional errors after thousands of layers are fused together.For example, just a 1% error of each layer (e.g., using layers around 10um thick) to build a part 10 cm tall, would introduce the error as largeas 1 mm. With devices herein, a mechanical device (e.g., a mechanicalplanerizer) that utilizes an angled blade, removes any excess thicknessof the layer of build and support material, thereby leveling the freshlytransfused layer.

After a layer is transfused onto the part, the structure can be heatedto complete the fusing process. Immediately afterward, the stack oflayers is shuttled past the mechanical planerizer to remove any excessmaterial while the newly transfused layer is still soft. The layer isthen cooled, and then the platen is shuttled back to be preheated inpreparation for the next layer to be transfused. While the mechanicalplanerizer could also be applied after the layer has been cooled, thereaction loads on the blade are higher in that type of processing.

As shown, for example, in FIG. 1, exemplary three-dimensional (3-D)printers herein include, among other components, an intermediatetransfer surface, such as an intermediate transfer belt 110 (ITB)supported on rollers 112, a first printing component (e.g., developmentdevice 116), and a second printing component (e.g., development device114). Thus, as shown in FIG. 1, the first printing component 116 ispositioned to electrostatically transfer (by way of charge differencebetween the belt (produced by charge generator 128, for example) and thematerial being transferred) a first material 104, the build material,such as a (potentially dry) powder polymer-wax material (e.g., charged3-D toner) to the ITB 110. The second printing component 114 (which canalso be, for example, a photoreceptor) is also positioned toelectrostatically transfer a second material 105 (e.g., the supportmaterial, again such as a powder polymer-wax material (e.g., charged 3-Dtoner)) to a location of the ITB 110 where the first material 104 islocated on the ITB 110.

The support material 105 dissolves in solvents that do not affect thebuild material 104, to allow the printed 3-D structure 104 to beseparated from the support material 105 after the full 3-D item iscomplete. In the drawings, the combination of the build material 104 andthe support material 105 is shown as element 102, and is sometimesreferred to as a “developed layer.” The developed layer 102 of the buildmaterial 104 and the support material 105 is on a discrete area of theITB 110 and is in a pattern corresponding to the components of the 3-Dstructure in that layer (and its associated support elements), where the3-D structure is being built, developed layer 102 by developed layer102.

Additionally, a platen 118 (which can be a surface or belt) is adjacentthe ITB 110. Patterned layers 102 of build and support material aretransferred from the development devices 114, 116 to the intermediatetransfer belt 110, and eventually to the platen 118 at a transfusestation 130.

As shown in FIG. 1, the transfuse station 130 is adjacent the ITB 110.The transfuse station 130 includes a roller 112, on one side of the ITB110, supporting the ITB 110. The transfuse station 130 is positioned toreceive the layers 102 as the ITB 110 moves to the transfuse station130. More specifically, the build material development station 116 thesupport material development station 114, and the transfuse station 130are positioned relative to the ITB 110 such that a layer 102 on the ITB110, when the ITB 110 is moving in a process direction, first passes thebuild material and support material development stations 114, 116, andthen passes the transfuse station 130.

As further shown in FIG. 1, such structures can include a transfuseheater 120, an optional fusing station 126, an optional curing station124, and an optional cooling station 146. The fusing station 126 appliespressure and/or heat to fuse the most recently transfused layer 102 tothe platen 118 or the layers present on the platen 118. The curingstation 124 is positioned to apply light (e.g. UV light) using a lightsource and/or heat using a heater to cure the layers. The coolingstation 146 blows potentially cooled air on the layer that has just beenfused and cured. The structure can also include a support materialremoval station 148.

FIG. 1 also illustrates a mechanical planer 144 is also separate fromthe ITB 110 and is positioned to contact and level the freestandingstack so as to make the top of the layer parallel to the flat surface ofthe platen 118. The mechanical planer 144 reduces the thickness of thefreestanding stack. The mechanical planer 144 comprises an elongatedstructure (e.g., an angled blade) and there is relative movement betweenthe mechanical planer 144 and the platen 118 in a direction parallel tothe flat surface of the platen 118. FIG. 1 also illustrates a feedbackloop 142 that is electrically connected to a thickness sensor 140 andthe mechanical planer 144. In some structures, the mechanical planer 144adjusts the amount of the build material and the support materialremoved from the layer based on the thickness of the layer on the platen118, as determined by the sensor 140.

As shown by the vertical arrow in FIG. 2, the platen 118 moves (usingmotors, gears, pulleys, cables, guides, etc. (all generally illustratedby item 118)) toward the ITB 110 to have the platen 118 make contactwith the ITB 110. The developed layer 102 and ITB 110 can optionally belocally heated by heater 120 to further help bring the developed layer102 to a “tacky” state prior to transfuse. In one example, the developedlayer 102 can be heated to a temperature higher than the glasstransition temperature (Tg) but short of the melt or fuse temperature(Tm) of the support and build materials, to allow the support and buildmaterials to become tacky to assist in transferring the layers 102 tothe platen 118 (or to existing layers 102 on the platen 118).

The platen 118 can also optionally be heated by heater 120 toapproximately the same temperature, and then be contacted synchronouslywith the tacky layer 102 as it translates through the ITB-platen nip(the transfuse nip 130). Thereby, the ITB 110 transfers one of thedeveloped layer 102 of the build material 104 and the support material105 to the platen 118 each time the platen 118 contacts the ITB 110, tosuccessively form developed layers 102 of the build material 104 and thesupport material 105 on the platen 118.

Therefore, the build and support material that is electrostaticallyprinted in a pattern on the ITB by each separate development device 114,116, is combined together in the developed layers 102 to represent aspecific pattern having a predetermined length. Thus, as shown in FIG.2, each of the developed layers 102 has a leading edge 134 orientedtoward the processing direction in which the ITB 110 is moving(represented by arrows next to the ITB 110) and a trailing edge 136opposite the leading edge 134.

More specifically, as shown in FIG. 2, at the transfuse nip 130, theleading edge 134 of the developed layer 102 within the transfuse nip 130begins to be transferred to a corresponding location of the platen 118.Thus, in FIG. 2, the platen 118 moves to contact the developed layer 102on the ITB 110 at a location where the leading edge 134 of the developedlayer 102 is at the lowest location of the roller of the transfuse nip130. Thus, in this example, the trailing edge 136 of the developed layer102 has not yet reached the transfuse nip 130 and has not, therefore,yet been transferred to the platen 118.

As shown in FIG. 3, the platen 118 moves synchronously with the ITB 110(moves at the same speed and the same direction as the ITB 110) eitherby moving or rotating the platen vacuum belt, to allow the developedlayers 102 to transfer cleanly to the platen 118, without smearing. InFIG. 3, the trailing edge 136 of the developed layer 102 is the onlyportion that has not yet reached the transfuse nip 130 and has not,therefore, been transferred to the platen 118.

Then, as the ITB 110 moves in the processing direction, the platen 118moves at the same speed and in the same direction as the ITB 110, untilthe trailing edge 136 of the developed layer 102 reaches the bottom ofthe roller of the transfuse nip 130, at which point the platen 118 movesaway from the ITB 110 and over to the fusing station 126, as shown inFIG. 4. The fusing station 126 is optional (as all needed fusing can beperformed by the transfuse station 130) and can be a non-contact (e.g.,infrared (IR)) heater, or a pressure heater, such as a fuser roller thatheats and presses the layer(s) 102. If the fusing station 126 is apressure roller, the platen 118 moves synchronously as the rollerrotates, heating and pressing to fuse the developed layer 102 to theplaten 118. This synchronous movement between the platen 118 and the ITB110 (and heated roller 126) causes the pattern of support and buildsmaterials (102) that are printed by the development devices 116, 114 tobe transferred precisely from the ITB 110 and fused to the other layers102 on the platen 118, without distortion or smearing.

As shown in FIG. 5, the sensor 140 detects the thickness and topographyof the layer on the platen. The sensor 140 can be any form of thicknessmeasurement device including contact and non-contact devices, and iscalibrated to only detect the thickness of the very top layer on theplaten 118.

For example, the sensor 140 can include a laser and camera, and uselaser profiling (laser triangulation), where object profiles aremeasured using a laser sheet-of-light (triangulation) technique. Withlaser profiling sensors 140, a laser line is projected on the object,and the resulting sensor image is evaluated by a camera core andconverted into a single height profile by scanning the laser line overthe object. Thus, a complete height image of the object can be acquired.The sensor 140 is capable of delivering position data as well asadditional features (e.g., intensity, line width) without sacrificingprofile speed.

In another example, the sensor 140 can use time-of-flight thicknessmeasurement that creates distance data using the principle where theentire “scene” is captured with each laser or light pulse (again, usinga laser source and camera). Here, a 3-D camera system covers distancesfrom a few meters up to several meters, depending on the detectormaterial being used. At the heart of the camera is an advanced sensortechnology employing the time-of-flight distance measurement principlewhere infrared light from the camera's internal lighting source isreflected by objects in the scene and travels back to the camera whereits precise time of arrival is measured independently by each of tens ofthousands of sensor pixels.

Also, the sensor 140 can be a light sensor that uses structured light,where a light source projects a narrow band of light onto athree-dimensionally shaped surface to produce a line of illuminationthat appears distorted from other perspectives than that of theprojector, and can be used for an exact geometric reconstruction of thesurface shape (light section). The structured light sensor 140 can alsoprovide a faster and more versatile process by projecting patternsconsisting of many stripes at once, or of arbitrary fringes, as thisallows for the acquisition of a multitude of samples simultaneously.Seen from different viewpoints, the pattern appears geometricallydistorted due to the surface shape of the object.

Further, the sensor 140 can be a stereoscopic (stereo vision) systemthat uses two cameras displaced horizontally from one another. Together,these cameras obtain two different views of a scene from which a 3-Dimage can be reconstructed.

In another alternative, the sensor 140 can be a contact-based gelsightsensing device that has a slab of clear elastomer covered with areflective skin. When an object presses on the reflective skin, thereflective skin distorts to take on the shape of the object's surface.When viewed from behind (through the elastomer slab), the reflectiveskin appears as a relief replica of the surface. A camera is included inthe sensor 140 to record an image of this relief, using illuminationfrom red, green, and blue light sources at three different positions. Aphotometric stereo algorithm that is tailored to the device is then usedto reconstruct the surface.

As shown in FIG. 6, the mechanical planer 144 is positioned to contactand level the layer 102 on the platen 118 as the platen 118 moves pastthe mechanical planer (as shown by the horizontal arrow in FIG. 6). Themechanical planer 144 makes the top of the layer 102 parallel to theflat surface of the platen 118 and reduces the thickness of the layer102. The feedback loop 142, that is electrically connected to the sensor140 and the mechanical planer 144, allows the mechanical planer 144 toadjust the amount of build and support material removed from the layer102 based on the thickness/topography of the layer 102 on the platen118, as determined by the sensor 140.

As shown in FIG. 7, the platen moves to the optional curing station 124,which applies light and/or heat to the 3-D structure to bond thedeveloped layers 102 in the freestanding stack 106 to one another on theplaten 118. The selective use of heaters, lights, and other componentsin the bonding station 124 will vary depending upon the chemical makeupof the developed layers 102. In one example, the build material 104 caninclude UV curable toners. Therefore, as shown in FIG. 7, in one examplethe curing station 124 can cure such materials 104 by heating thematerials 104 to a temperature between their glass transitiontemperature and their melting temperature, and then applying UV light tocross-link the polymers within the materials 104, thereby creating arigid structure. Those ordinarily skilled in the art would understandthat other build and support materials would utilize other bondingprocessing and bonding components, and that the foregoing is presentedonly as one limited example; and the devices and methods herein areapplicable to all such bonding methods and components, whether currentlyknown or developed in the future.

Additionally, as shown in FIG. 8, the cooling station 146 (or even acooling pause in processing) can be used to cool the layers 102 on theplaten 118 between layer 102 transfers. The cooling station can blow air(potentially cooled and dehumidified air) on the layer 102 on the platen118, as shown in FIG. 8.

The platen 118 can move to the fusing station 126, curing station 124,and cooling station 146 after each time the ITB 110 transfers each ofthe developed layers 102 to the platen 118 to independently fuse, cure,and cool each of the developed layers 102. In other alternatives, theplaten 118 may only move to the fusing station 126, curing station 124,and cooling station 146 after a specific number (e.g., 2, 3, 4, etc.) ofthe developed layers 102 have been placed on the platen 118 to allowmultiple developed layers 102 to be simultaneously fused, cured, andcooled.

At this point in processing the platen 118 can return to the transfusenip 130 to receive the next layer 102 from the ITB 110. Thus, theprocessing in FIGS. 2-8 is repeated to fuse multiple developed layers102 into a stack 106, as shown in FIG. 9. As the stack 106 of thedeveloped layers 102 grows, additional developed layers 102 are formedon top of the stack 106, as shown in FIG. 10, the thickness of the toplayer 102 of such additional developed layers 106 is measured by thesensor 140, and leveled by the mechanical planer 144, as shown in FIG.11.

FIG. 12 shows an expanded view of the mechanical planer 144 and thestack 106 on the platen 118. As described above, each of the layers 102is made up of some build material 104 and some support material 105. Asshown in FIG. 12, the mechanical planer 144 includes an angled blade 164(e.g., a blade 164 positioned at a non-parallel and non-perpendicularangle to the flat surface 119 of the platen 118). The blade 164 has abeveled edge is rests against to a linear slide 168, which is in turnsupported by the blade support 160.

The blade 164 is movable, and an actuator 166 is connected to themovable blade 164. The actuator 166 moves the movable blade 164 towardand away from the platen 118 to remove a greater amount or a lesseramount of the top layer 102 of the stack 106 as the platen moves pastthe mechanical planer 144 (shown by horizontal arrow in FIG. 12). Theactuator 166 (such as a stepper motor, a hydraulic actuator, a pneumaticactuator, a magnetic actuator, etc.) is connected to the blade 164 andis used to advance and retract the blade 164 through an angled opening172 in the blade support 160 as needed to ensure that the properleveling “height” is achieved (based on the thickness/topographydetected by the sensor 140). Thus, as can be seen in FIG. 12, theportion of the top layer 102 that is to the right of the blade 164 hasbeen scraped by the blade 164 and is therefore relatively thinner andparallel to the top surface 119 of the platen 118; while the portion ofthe top layer 102 that is to the left of the blade 164 has not yet beenscraped by the blade 164 and is therefore relatively thicker and notfully parallel to the top surface 119 of the platen 118.

This structure can additionally include a collection tray 170 adjacentthe mechanical planer 144. The collection tray 170 is positioned tocollect the build and support material 104, 105 removed from the toplayer 102 by the mechanical planer 144. In the drawings, the top layer102 is the layer 102 in the stack 106 that is furthest from the platen118.

Also, a cleaning structure can be located in a fixed position within theopening 172, and the cleaning structure contacts and cleans the movableblade 164 as the actuator 166 moves the movable blade 164 past thecleaning structure 162. The cleaning structure 162 can be a fibrousmaterial, such as a natural or artificial sponge, brush, cloth, pad,abrasive surface, etc. At a predefined interval, the stepper motor 166is actuated to rub the blade 164 edge along (e.g., back and forthacross) the scrubbing pad 162 in order to remove any cooled material104, 105 that may build up on the blade 164. This material 104, 105,will fall into the container 170 located under the blade 164 stationwhile the cleaning operation is carried out.

The processing described above is repeated many times to form thefreestanding stack 106 of build and support material 104, 105 as shownin FIG. 13. FIG. 13 illustrates an overlay showing portions of supportmaterial 105 and build material 104 within the accumulation of thefreestanding stack 106. Such may or may not be visible, and is onlyillustrated to show one exemplary way in which such build and supportmaterials 104, 105 may be arranged.

The 3-D structure of the freestanding stack 106 can be output to allowmanual removal of the support material 105 using external heated bath;or processing can proceed as shown in FIG. 13-15. More specifically, inFIG. 13, the support material removal station 148 is positioned toreceive the now bonded 3-D freestanding stack 106 on the platen 118. Thesupport material removal station 148 applies a solvent 156 thatdissolves the support material 105 without affecting the build material104. Again, as noted above, the solvent utilized will depend upon thechemical makeup of the build material 104 and the support material 105.FIG. 14 illustrates the processing where about half of the supportmaterial 105 remains, and a portion of the build material 104 protrudesfrom the remaining stack of support material 105. FIG. 15 illustratesprocessing after the support material removal station 148 has appliedsufficient solvent 156 to dissolve all the support material 105, leavingonly the build material 104 remaining, which leave a completed 3-Dstructure made of only the build material 104.

FIGS. 16-17 illustrate an alternative 3-D electrostatic printingstructure herein that includes a planar transfuse station 138 in placeof the transfuse nip 130 shown in FIG. 1. As shown in FIG. 16, theplanar transfuse station 138 is a planar portion of the ITB 110 that isbetween rollers 112 and is parallel to the platen 118. As shown in FIG.16, with this structure, when the platen 118 moves to contact the planartransfuse station 138, all of the developed layer 102 is transferredsimultaneously to the platen 118 or partially formed stack 106, avoidingthe rolling transfuses process shown in FIGS. 2 and 3. FIG. 17illustrates that the mechanical planer 144 levels the top layer 102 tokeep the layers 102 within the stack 106 parallel with the upper surface119 of the platen 118, as discussed above.

Similarly, as shown in FIGS. 18 and 19, a drum 158 could be used inplace of the ITB 110, with all other components operating as describedherein. Thus, the drum 158 could be an intermediate transfer surfacereceiving material from development stations 114, 116, as describedabove, or could be a photoreceptor and operate as the photoreceptor 256described below operates, by maintaining a latent image of charge andreceiving materials from development devices 254. As shown in FIG. 19,the mechanical planer 144 levels the layer 102 to keep the layers 102within the stack 106 parallel with the upper surface 119 of the platen118, as discussed above.

FIG. 20 illustrates many components of 3-D printer structures 204herein. The 3-D printing device 204 includes a controller/tangibleprocessor 224 and a communications port (input/output) 214 operativelyconnected to the tangible processor 224 and to a computerized networkexternal to the printing device 204. Also, the printing device 204 caninclude at least one accessory functional component, such as a graphicaluser interface (GUI) assembly 212. The user may receive messages,instructions, and menu options from, and enter instructions through, thegraphical user interface or control panel 212.

The input/output device 214 is used for communications to and from the3-D printing device 204 and comprises a wired device or wireless device(of any form, whether currently known or developed in the future). Thetangible processor 224 controls the various actions of the printingdevice 204. A non-transitory, tangible, computer storage medium device210 (which can be optical, magnetic, capacitor based, etc., and isdifferent from a transitory signal) is readable by the tangibleprocessor 224 and stores instructions that the tangible processor 224executes to allow the computerized device to perform its variousfunctions, such as those described herein. Thus, as shown in FIG. 20, abody housing has one or more functional components that operate on powersupplied from an alternating current (AC) source 220 by the power supply218. The power supply 218 can comprise a common power conversion unit,power storage element (e.g., a battery, etc), etc.

The 3-D printing device 204 includes at least one marking device(printing engine(s)) 240 that deposits successive layers of build andsupport material on a platen as described above, and are operativelyconnected to a specialized image processor 224 (that is different than ageneral purpose computer because it is specialized for processing imagedata). Also, the printing device 204 can include at least one accessoryfunctional component (such as a scanner 232) that also operates on thepower supplied from the external power source 220 (through the powersupply 218).

The one or more printing engines 240 are intended to illustrate anymarking device that applies build and support materials (toner, etc.)whether currently known or developed in the future and can include, forexample, devices that use an intermediate transfer belt 110 (as shown inFIG. 21).

Thus, as shown in FIG. 21, each of the printing engine(s) 240 shown inFIG. 20 can utilize one or more potentially different (e.g., differentcolor, different material, etc.) build material development stations116, one or more potentially different (e.g., different color, differentmaterial, etc.) support material development stations 114, etc. Thedevelopment stations 114, 116 can be any form of development station,whether currently known or developed in the future, such as individualelectrostatic marking stations, individual inkjet stations, individualdry ink stations, etc. Each of the development stations 114, 116transfers a pattern of material to the same location of the intermediatetransfer belt 110 in sequence during a single belt rotation (potentiallyindependently of a condition of the intermediate transfer belt 110)thereby, reducing the number of passes the intermediate transfer belt110 must make before a full and complete image is transferred to theintermediate transfer belt 110. While FIG. 21 illustrates fivedevelopment stations adjacent or in contact with a rotating belt (110),as would be understood by those ordinarily skilled in the art, suchdevices could use any number of marking stations (e.g., 2, 3, 5, 8, 11,etc.).

One exemplary individual electrostatic development station 114, 116 isshown in FIG. 22 positioned adjacent to (or potentially in contact with)intermediate transfer belt 110. Each of the individual electrostaticdevelopment stations 114, 116 includes its own charging station 258 thatcreates a uniform charge on an internal photoreceptor 256, an internalexposure device 260 that patterns the uniform charge into a latent imageof charge, and an internal development device 254 that transfers buildor support material to the photoreceptor 256 in a pattern matching thecharge latent image. The pattern of build or support material is thendrawn from the photoreceptor 256 to the intermediate transfer belt 110by way of an opposite charge of the intermediate transfer belt 110relative to the charge of the build or support material, that is usuallycreated by a charge generator 128 on the opposite side of theintermediate transfer belt 110.

As shown in U.S. Pat. No. 8,488,994, an additive manufacturing systemfor printing a 3-D part using electrophotography is known. The systemincludes a photoconductor component having a surface, and a developmentstation, where the development station is configured to developed layersof a material on the surface of the photoconductor component. The systemalso includes a transfer medium configured to receive the developedlayers from the surface of the rotatable photoconductor component, and aplaten configured to receive the developed layers from the transfercomponent in a layer-by-layer manner to print the 3-D part from at leasta portion of the received layers.

With respect to UV curable toners, as disclosed in U.S. Pat. No.7,250,238 it is known to provide a UV curable toner composition, as aremethods of utilizing the UV curable toner compositions in printingprocesses. U.S. Pat. No. 7,250,238 discloses various toner emulsionaggregation processes that permit the generation of toners that inembodiments can be cured, that is by the exposure to UV radiation, suchas UV light of has about 100 nm to about 400 nm. In U.S. Pat. No.7,250,238, the toner compositions produced can be utilized in variousprinting applications such as temperature sensitive packaging and theproduction of foil seals. In U.S. Pat. No. 7,250,238 embodiments relateto a UV curable toner composition comprised of an optional colorant, anoptional wax, a polymer generated from styrene, and acrylate selectedfrom the group consisting of butyl acrylate, carboxyethyl acrylate, anda UV light curable acrylate oligomer. Additionally, these aspects relateto a toner composition comprised of a colorant such as a pigment, anoptional wax, and a polymer generated from a UV curable cycloaliphaticepoxide.

Moreover, U.S. Pat. No. 7,250,238 discloses a method of forming a UVcurable toner composition comprising mixing a latex containing a polymerformed from styrene, butyl acrylate, a carboxymethyl acrylate, and a UVcurable acrylate with a colorant and wax; adding flocculant to thismixture to optionally induce aggregation and form toner precursorparticles dispersed in a second mixture; heating the toner precursorparticles to a temperature equal to or higher than the glass transitiontemperature (Tg) of the polymer to form toner particles; optionallywashing the toner particles; and optionally drying the toner particles.A further aspect relates to the toner particles produced by this method.

While some exemplary structures are illustrated in the attacheddrawings, those ordinarily skilled in the art would understand that thedrawings are simplified schematic illustrations and that the claimspresented below encompass many more features that are not illustrated(or potentially many less) but that are commonly utilized with suchdevices and systems. Therefore, Applicants do not intend for the claimspresented below to be limited by the attached drawings, but instead theattached drawings are merely provided to illustrate a few ways in whichthe claimed features can be implemented.

Many computerized devices are discussed above. Computerized devices thatinclude chip-based central processing units (CPU's), input/outputdevices (including graphic user interfaces (GUI), memories, comparators,tangible processors, etc.) are well-known and readily available devicesproduced by manufacturers such as Dell Computers, Round Rock Tex., USAand Apple Computer Co., Cupertino Calif., USA. Such computerized devicescommonly include input/output devices, power supplies, tangibleprocessors, electronic storage memories, wiring, etc., the details ofwhich are omitted herefrom to allow the reader to focus on the salientaspects of the systems and methods described herein. Similarly,printers, copiers, scanners and other similar peripheral equipment areavailable from Xerox Corporation, Norwalk, Conn., USA and the details ofsuch devices are not discussed herein for purposes of brevity and readerfocus.

The terms printer or printing device as used herein encompasses anyapparatus, such as a digital copier, bookmaking machine, facsimilemachine, multi-function machine, etc., which performs a print outputtingfunction for any purpose. The details of printers, printing engines,etc., are well-known and are not described in detail herein to keep thisdisclosure focused on the salient features presented. The systems andmethods herein can encompass systems and methods that print in color,monochrome, or handle color or monochrome image data. All foregoingsystems and methods are specifically applicable to electrostatographicand/or xerographic machines and/or processes.

For the purposes of this invention, the term fixing means the drying,hardening, polymerization, crosslinking, binding, or addition reactionor other reaction of the coating. In addition, terms such as “right”,“left”, “vertical”, “horizontal”, “top”, “bottom”, “upper”, “lower”,“under”, “below”, “underlying”, “over”, “overlying”, “parallel”,“perpendicular”, etc., used herein are understood to be relativelocations as they are oriented and illustrated in the drawings (unlessotherwise indicated). Terms such as “touching”, “on”, “in directcontact”, “abutting”, “directly adjacent to”, etc., mean that at leastone element physically contacts another element (without other elementsseparating the described elements). Further, the terms automated orautomatically mean that once a process is started (by a machine or auser), one or more machines perform the process without further inputfrom any user. In the drawings herein, the same identification numeralidentifies the same or similar item.

It will be appreciated that the above-disclosed and other features andfunctions, or alternatives thereof, may be desirably combined into manyother different systems or applications. Various presently unforeseen orunanticipated alternatives, modifications, variations, or improvementstherein may be subsequently made by those skilled in the art which arealso intended to be encompassed by the following claims. Unlessspecifically defined in a specific claim itself, steps or components ofthe systems and methods herein cannot be implied or imported from anyabove example as limitations to any particular order, number, position,size, shape, angle, color, or material.

What is claimed is:
 1. A three-dimensional (3-D) printer comprising: anintermediate transfer surface; a build material development stationpositioned to transfer build material to said intermediate transfersurface; a support material development station positioned to transfersupport material to said intermediate transfer surface, said buildmaterial development station and said support material developmentstation transfer layers of said build material and said support materialto said intermediate transfer surface; a platen having a flat surfacepositioned to contact said intermediate transfer surface, saidintermediate transfer surface transfers a layer of said build materialand said support material to said platen, or existing layers on saidplaten, each time said platen, or said existing layers, contact saidintermediate transfer surface; and a mechanical planer positioned tocontact and level said layer on said platen as said platen moves pastsaid mechanical planer.
 2. The 3-D printer according to claim 1, saidmechanical planer comprises a blade positioned at a non-parallel andnon-perpendicular angle to said flat surface of said platen.
 3. The 3-Dprinter according to claim 1, said mechanical planer comprises a movableblade and an actuator connected to said movable blade, said actuatormoves said movable blade toward and away from said platen.
 4. The 3-Dprinter according to claim 3, said mechanical planer comprises acleaning structure in a fixed position, said cleaning structure contactsand cleans said movable blade as said actuator moves said movable bladepast said cleaning structure.
 5. The 3-D printer according to claim 1,further comprising a collection tray adjacent said mechanical planer,said collection tray is positioned to collect said build material andsaid support material removed from said layer by said mechanical planer.6. The 3-D printer according to claim 1, said mechanical planer makesthe top of said layer parallel to said flat surface of said platen. 7.The 3-D printer according to claim 1, said mechanical planer reduces thethickness of said layer.
 8. A three-dimensional (3-D) printercomprising: an intermediate transfer surface; a build materialdevelopment station positioned to transfer build material to saidintermediate transfer surface; a support material development stationpositioned to transfer support material to said intermediate transfersurface, said build material development station and said supportmaterial development station transfer layers of said build material andsaid support material to said intermediate transfer surface; a platenhaving a flat surface positioned to contact said intermediate transfersurface, said intermediate transfer surface transfers a layer of saidbuild material and said support material to said platen, or existinglayers on said platen, each time said platen, or said existing layers,contact said intermediate transfer surface; a sensor detecting thethickness of said layer on said platen; a mechanical planer positionedto contact and level said layer on said platen as said platen moves pastsaid mechanical planer; and a feedback loop electrically connected tosaid sensor and said mechanical planer, said mechanical planer adjuststhe amount of material removed from said layer based on said thicknessof said layer on said platen, as determined by said sensor.
 9. The 3-Dprinter according to claim 8, said mechanical planer comprises a bladepositioned at a non-parallel and non-perpendicular angle to said flatsurface of said platen.
 10. The 3-D printer according to claim 8, saidmechanical planer comprises a movable blade and an actuator connected tosaid movable blade, said actuator moves said movable blade toward andaway from said platen.
 11. The 3-D printer according to claim 10, saidmechanical planer comprises a cleaning structure in a fixed position,said cleaning structure contacts and cleans said movable blade as saidactuator moves said movable blade past said cleaning structure.
 12. The3-D printer according to claim 8, further comprising a collection trayadjacent said mechanical planer, said collection tray is positioned tocollect said build material and said support material removed from saidlayer by said mechanical planer.
 13. The 3-D printer according to claim8, said mechanical planer makes the top of said layer parallel to saidflat surface of said platen.
 14. The 3-D printer according to claim 8,said mechanical planer reduces said thickness of said layer.
 15. Athree-dimensional (3-D) printer comprising: an intermediate transferbelt (ITB) having a transfuse nip; a build material development stationpositioned to electrostatically transfer build material to said ITB; asupport material development station positioned to electrostaticallytransfer support material to said ITB, said build material developmentstation and said support material development station transfer layers ofsaid build material and said support material to said ITB; a platenhaving a flat surface positioned to contact said ITB, said ITB transfersa layer of said build material and said support material to said platen,or existing layers on said platen, each time said platen, or saidexisting layers, contact said transfuse nip of said ITB; a sensordetecting the thickness of said layer on said platen; a mechanicalplaner positioned to contact and level said layer on said platen as saidplaten moves past said mechanical planer; and a feedback loopelectrically connected to said sensor and said mechanical planer, saidmechanical planer adjusts the amount of said build material and saidsupport material removed from said layer based on said thickness of saidlayer on said platen, as determined by said sensor.
 16. The 3-D printeraccording to claim 15, said mechanical planer comprises a bladepositioned at a non-parallel and non-perpendicular angle to said flatsurface of said platen.
 17. The 3-D printer according to claim 15, saidmechanical planer comprises a movable blade and an actuator connected tosaid movable blade, said actuator moves said movable blade toward andaway from said platen.
 18. The 3-D printer according to claim 17, saidmechanical planer comprises a cleaning structure in a fixed position,said cleaning structure contacts and cleans said movable blade as saidactuator moves said movable blade past said cleaning structure.
 19. The3-D printer according to claim 15, further comprising a collection trayadjacent said mechanical planer, said collection tray is positioned tocollect said build material and said support material removed from saidlayer by said mechanical planer.
 20. The 3-D printer according to claim15, said mechanical planer makes the top of said layer parallel to saidflat surface of said platen and reduces said thickness of said layer.